Since the first observation of coherent quantum behaviour in a superconducting qubit, now
more than 20 years ago, there have been substantial developments in the field of …

Quantum information is vulnerable to environmental noise and experimental imperfections,
hindering the reliability of practical quantum information processors. Therefore, quantum …

The ambition of harnessing the quantum for computation is at odds with the fundamental
phenomenon of decoherence. The purpose of quantum error correction (QEC) is to …

We present a comprehensive architectural analysis for a proposed fault-tolerant quantum
computer based on cat codes concatenated with outer quantum error-correcting codes. For …

The accuracy of logical operations on quantum bits (qubits) must be improved for quantum
computers to outperform classical ones in useful tasks. One method to achieve this is …

Quantum superpositions of macroscopically distinct classical states—so-called Schrödinger
cat states—are a resource for quantum metrology, quantum communication and quantum …

Encoding a qubit in logical quantum states with wave functions characterized by disjoint
support and robust energies can offer simultaneous protection against relaxation and pure …

The unique features of quantum theory offer a powerful new paradigm for information
processing. Translating these mathematical abstractions into useful algorithms and …

By applying a microwave drive to a specially designed Josephson circuit, we have realized
a double-well model system: a Kerr oscillator submitted to a squeezing force. We have …

The development of robust architectures capable of large-scale fault-tolerant quantum
computation should consider both their quantum error-correcting codes and the underlying …